In their methods of growth cities conform always to biological laws, all growth being either central or axial. In some cities central growth occurs first and in others axial growth, but all cities illustrate both forms of growth and in all cases central growth includes some axial growth, and axial growth some central growth. Central growth consists of the clustering of utilities around any point of attraction and is based on proximity, while axial growth is the result of transportation facilities and is based on accessibility. A continual contest exists between axial growth pushing out from the. centre along transportation lines and central growth, constantly following and obliterating it, while new projections are being made further out the various axes. The normal result of axial and central growth is a star-shaped city, growth extending first along the main thoroughfares radiating from the centre, and later filling in the parts lying between. The modifications of the shape of cities come chiefly from topography, the lesser influences being an uneven development of some one factor of growth or individual ownership of land.

Portland, Ore. Showing first growth along river bank.

Portland, Ore. Showing first growth along river bank.

Turning first to axial growth, the frame-work of a city is laid down by its water courses, turnpikes and railroads. Of these, the turnpikes in the older cities are of chief importance. Before the days of railroads these controlled so much outside traffic that their city ends became the principal business streets, and many still maintain their supremacy. For example, Broadway in New York was part of the old Albany turnpike which runs on to Montreal; Washington Street in Boston was the turnpike to New York, which in passing through Providence was known as Westminster Street; Main Street in Hartford was the New Haven turnpike, which continued north of Hartford as the Albany and Windsor turnpikes; Montgomery Street in Jersey City was the through road from New York to the south, which, continuing out Newark Avenue, runs through Newark as Broad Street, and so on to Philadelphia; the National Pike built from Washington to the west one hundred years ago, runs through Wheeling as Market Street, Columbus as Broad Street, Indianapolis as Washington Street, Terre Haute as Main Street, and so on; and in Kansas City Main Street was the old Sante Fe trail, running a thousand miles from the Missouri River to Santa Fe.

Turnpikes are the natural outlets for residences forced away from the business centre and in small towns attract the inhabitants by the human interest and protection of the passing travel. Growth along turnpikes continues to a point where the inconvenience of living so far out of town more than offsets the attractions of the turnpike when back streets are laid out.

Wheeling, W. Va., in 1845. Showing first growth parallel to river. The road over the hill is the National Pike.

Wheeling, W. Va., in 1845. Showing first growth parallel to river. The road over the hill is the National Pike.

Steam railroads affect city land in three ways: First, by their terminals; second, by their lines as barriers to growth or communication; and, third, by their lines as influencing land immediately adjacent. The central effect of a passenger depot in a small city is to attract cheap hotels and shops, such abnormal cases as the vacant lots opposite the Union depots in Toledo and New Haven being due to railroad ownership of the land. In the larger cities high class hotels gather near the principal depots, as in New York and Boston, and in England, where they are frequently built as a part of the railroad station itself. The axial effect of railroad depots is of great importance in the smaller towns, where the depot constitutes one of the strongest single forces attracting traffic within the city. The distribution of this axial effect depends upon whether the travel to and from the depot is concentrated on one principal street, or whether the streams of travel pass through a large number of streets. Ordinarily the railroad terminal occupies so much area and blocks so many streets that it is most conveniently approached by one street. The axial effect of a depot is more easily noted when it is located a few blocks from a through traffic street than if located on such a street, the travel off the. through street being then directly due to the depot and not being mingled with the general travel. In some cases a depot blocks the end or furnishes the beginning of a street which would for other reasons have been a good street, but which is greatly strengthened by the depot, as with 17th Street in Denver. Freight depots are commonly a part of passenger terminals and attract warehouses, heavy wholesalers and tenements.